About Retrofit Planner

We build free, independent tools to help UK homeowners make informed decisions about home energy improvements. No sales pitch, no hidden agenda — just clear data and honest calculations.

Why we built this

The UK government is pushing millions of homeowners to upgrade their heating and insulation over the next decade. Heat pumps, insulation, solar panels, EPC improvements — there's a lot to think about and the information is scattered across dozens of government websites, trade body publications, and installer marketing pages.

We built Retrofit Planner to bring that information together into simple, interactive tools. Instead of reading a 40-page Energy Saving Trust report, you answer five questions and get a personalised estimate in seconds. Instead of visiting three different government websites to check grant eligibility, you use one checker that covers them all.

Where our data comes from

Every calculation on this site is based on published, official UK data sources. We never make up numbers or use unverifiable claims. Our primary sources are:

• Ofgem — energy prices from the quarterly price cap announcements. We update our calculators within days of each new price cap taking effect.
• Energy Saving Trust (EST) — installation costs, typical savings by property type, and energy efficiency recommendations. EST is the UK's leading independent authority on domestic energy efficiency.
• BEIS / DESNZ — government department data on energy consumption by property type, building age, and region. Published as open data under the Open Government Licence.
• BRE (Building Research Establishment) — the Standard Assessment Procedure (SAP) methodology used for EPC calculations.
• GOV.UK — grant scheme details, eligibility criteria, and application processes for the Boiler Upgrade Scheme, ECO4, and other programmes.

For full details on how we use each data source, see our methodology page.

How we make money

Transparency matters to us. Every calculator is completely free to use with no sign-up required. We make money in two ways:

• Installer referrals — when you click "get quotes" after using a calculator, we may connect you with MCS-certified installers. We receive a referral fee if you proceed with a quote. The installers we recommend are independently certified and we never let referral fees influence our calculator results.
• Product recommendations — some pages include links to relevant products (smart thermostats, insulation materials). These are affiliate links and we earn a small commission if you purchase. We only recommend products we believe are genuinely useful.

Our calculator results are never influenced by commercial relationships. The numbers come from official data sources and the calculations run entirely in your browser — we don't adjust results to favour any particular installer, product, or outcome.

Our calculators

We currently offer the following free tools, with more in development:

• Heat Pump Cost Calculator — installation costs, grant deduction, running costs vs gas, payback period
• Insulation Savings Calculator — savings by insulation type, costs, grant eligibility
• EPC Improvement Planner — cheapest path to a better EPC rating (coming soon)
• Solar Panel ROI Calculator — generation, savings, and payback (coming soon)
• Boiler vs Heat Pump Comparison — lifetime cost comparison (coming soon)
• Grant Eligibility Checker — check all available energy grants (coming soon)

Contact

Have a question, suggestion, or spotted an error in our calculations? We'd love to hear from you. Email us at hello@retrofitplanner.co.uk.

If you're a journalist or researcher and would like to reference our data or tools, please see our methodology page for details on our data sources and calculation methods.